KR950013418B1 - Recording apparatus - Google Patents

Abstract

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Description

Recorder

1 and 2 are cross-sectional views showing the main parts of the conventional recording apparatuses;

3, 4, 5, and 6 are cross-sectional views showing examples of main parts of different recording apparatuses according to the present invention.

* Explanation of symbols for main parts of the drawings

1: electrostatic latent image retainer 2: toner particle

2 ': remaining toner after transfer 3: developer

4: toner carrier 5: transfer device

6: image support 8: electric field removal lamp

9: corona charge 10: exposure means

13: brush roller 14: brush

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic recording apparatus, and more particularly, to a cleanerless recording apparatus for performing image recording without using a cleaning apparatus for recovering toner remaining after transfer.

In the electrophotographic recording apparatus, a recording apparatus (hereinafter referred to as a "cleaner-less recording apparatus") which recovers the toner remaining after transfer by the developing apparatus (means) in the developing apparatus at the same time is described in, for example, Japanese Patent Laid-Open No. 59-133573 It is known by Japanese Unexamined Patent Publication No. 59-157661.

These publications disclose the basic technical idea of a cleaner-less recording device. And the goal is summarized as follows.

In other words, as shown in the cross-sectional view of the configuration of the main portion in Fig. 1, the reverse developing method is often used in an electrophotographic printer represented by a laser printer.

In this reversal development method, the toner particles 2 charged at the same polarity as the electrostatic latent image retainer (photosensitive member) 1 are used, and the portion (or the amount of electric charge) on the surface of the electrostatic latent image retainer 1 does not exist. The toner particles 2 are attached to the small portion, and the toner particles 2 are not attached to the portion where the charge exists.

In order to realize such selective toner adhesion, most of the potential Vo and the non-charged portion of the surface of the electrostatic latent image retainer 1 described above on the toner carrier 4 in the developing apparatus (developing means) 3 are realized. Voltage between transitions of

Vb (| Ve | 〈| Vb | Vo |)

Is applied to suppress toner adhesion to the electrostatic latent image retainer 1 by the electric field between the charged portion on the surface of the electrostatic latent image retainer 1 and the toner carrier 4.

On the other hand, the toner 2 is attached to the electrostatic latent image retainer 1 by an electric field between the non-charged portion on the surface of the electrostatic latent image retainer 1 and the toner carrier 4.

The toner 2 attached to the electrostatic latent image retainer 1 is transferred to the image support 6 by the transfer device 5.

In general, not all of the toners are transferred in this transfer process, but the toner 2 'remaining after the transfer is distributed on the surface of the electrostatic latent image retainer 1 after transfer.

In a conventional electrophotographic apparatus, the toner 2 'remaining after the transfer is collected by the cleaner 7 shown by broken lines in FIG.

Subsequently, the electric field removal lamp 8 removes the electric charge on the surface of the latent electrostatic image retainer 1, and again, the electrostatic latent image forming process includes a uniform charging process by the charger 9 and an exposure process by the light beam 10. Will go through.

On the other hand, in the cleaner-less recording apparatus, since the cleaner 7 is not provided, the toner 2 'remaining after the transfer is brought into the developing process, and at the same time as the developing of the electrostatic latent image, the above-described post-transfer in the developing apparatus 3 The remaining toner 2 'is collected.

Strictly speaking, the toner 2 'remaining after the transfer in the charged portion (i.e., the unexposed portion or the non-image portion) of the latent image formed by the exposure of the light beam 10 has the same polarity as the latent image by the charger 9 It is surely played.

Therefore, the toner carrier 4 is moved to the toner carrier 4 side by an electric field (that is, an electric field due to the potential difference between Vo and Vb) that suppresses the transfer of the toner particles 2 from the toner carrier 4 to the electrostatic latent image bearing 1. Lose.

At the same time, the toner 2 'remaining after transfer in the non-charged portion (i.e., the exposure portion or the image portion) is subjected to a force directed from the toner carrier 4 to the electrostatic latent image retainer 1, and thus the electrostatic latent image retainer 1 Remains on the surface.

In the non-charged portion where the remaining toner 2 'remains after transfer, new toner particles 2 are transferred from the toner carrier 4, and cleaning is performed simultaneously with development.

In such a cleaner-less recording apparatus, the waste toner box for storing the cleaner 7 and the cleaned toner (i.e., waste toner) becomes unnecessary, so that the apparatus can be miniaturized and simplified.

In addition, the remaining toner 2 'is transferred to the developing apparatus 3 and used again, so that waste toner is not generated and is economical. The cleaning blade does not slip friction of the electrostatic latent image retainer 1. Therefore, there are many advantages such that the life of the electrostatic latent image retainer 1 can be extended.

However, in this cleanerless recording apparatus, ghost images may appear for the following reasons.

First, in a high humidity environment, the transfer efficiency is generally lowered because the paper as the image support 6 absorbs moisture and lowers resistance.

Therefore, a large amount of toner tends to remain on the surface of the latent electrostatic image retainer 1.

When the amount of toner 2 'remaining after the transfer becomes excessive, it cannot be completely cleaned by the developing apparatus 3, and the toner 2' remaining after the transfer remains in the non-image portion, Positive ghosts appear (hereafter referred to as positive ghosts or positive memory).

Second, when the amount of the toner 2 'remaining after the transfer becomes excessive, the remaining toner 2' after the transfer is shielded from the light beam 10 during the exposure process by the light beam 10, so that the electrostatic latent image retainer 1 The surface potential attenuation becomes insufficient, resulting in an intermediate potential state (referred to Ve ') between the potential Vo of the charged portion and the potential Ve of the non-charged portion.

The developing voltage becomes Vb-Ve 'in the region in the intermediate potential state and becomes smaller than the developing voltage Vb-Ve of the peripheral exposure portion, so that the toner from the toner carrier 4 to the electrostatic latent image retainer 1 The amount of movement is small compared to the surroundings.

Therefore, the toner image remaining after the transfer on the image portion of the transfer image appears only as a border and appears as a white image (hereinafter referred to as negative ghost or negative memory).

This phenomenon is particularly noticeable in halftone images consisting of a set of halftone images and line images.

On the other hand, Japanese Patent Laid-Open No. 62-203183 discloses that a ghost is removed by applying a voltage to a conductive brush 11 having a shape shown in cross section in FIG. 2 and making light contact with the surface of the electrostatic latent image retainer 1. It is open to the public.

That is, the conductive brush 11 applies the polarity voltage opposite to the counter electrode performance of the toner by the DC power supply 12 and sucks the toner 2 'remaining after the transfer into the brush 11 by electric force.

Accordingly, the amount of toner 2 'remaining after the transfer on the surface of the electrostatic latent image retainer 1 is greatly reduced and the above-described ghosting is prevented.

However, the following two problems arise in this manner.

(1) Instead of requiring a cleaner, it is necessary to separately install the homogenizing means 11 such as the brush described above. For this reason, even if the size of the device is reduced and the price is reduced, it is not necessarily a great effect. In particular, the conductive brush 11 is not easily adjusted at the time of manufacture and the fiber is easily bent, which leads to poor productivity and high cost. In addition, there is a problem that a new power source must be prepared in order to apply a voltage to the conductive brush 11.

(2) When the corona charger is used as the charging means 9 for uniformly charging the electrostatic latent image retainer 1, ozone is generated as a corona discharge product. This large amount of ozone is not only pleasant to the human body but also causes deterioration of components such as the latent latent image retainer 1.

As described above, in the conventional cleaner-free recording apparatus, there are problems such as miniaturization and low cost of the apparatus, and harmful discharge products. Therefore, it is difficult to say that practical satisfaction is obtained. It is therefore an object of the present invention to provide a recording apparatus which can be miniaturized and low in price.

In addition, an object of the present invention is to provide a recording device with high safety without generating harmful discharge products during use.

In addition, an object of the present invention is to provide a recording apparatus having high durability by eliminating the deterioration of components such as the electrostatic latent image retainer (1).

According to the present invention, in the cleaner-less recording apparatus having the above-described structure and function, the uniformity of the remaining toner image is provided in addition to the charging function required for the charging means.

That is, the present invention provides a charging means for uniformly charging the electrostatic latent image retainer and the surface of the electrostatic latent image retainer, means for forming an electrostatic latent image by attenuating a part of the electric charge on the surface of the electrostatic latent image retained by the charging means; Developing means for forming a toner image by adhering the toner to the electrostatic latent image, transfer means for transferring the formed toner image onto the image support member, and after displacing the toner image remaining on the surface of the electrostatic latent image retainer A recording apparatus comprising: a means for equalizing the residual toner on the surface of the toner, and collecting the toner inside the developing means by the developing means described above, and performing an electrostatic latent image development. It is characterized by including the function of homogenizing the residual toner phase.

In the cleaner-less recording apparatus according to the present invention, since the charging means also has the function of equalizing the residual toner image, it is unnecessary to install the residual toner cleaner and the means for equalizing the residual toner image, thereby realizing a true cleaner-free recording apparatus. .

As a result, when the charging means is constituted by a contactor to which voltage is applied, when the electrostatic latent image retainer is uniformly charged by the charging means, the remaining toner remaining on the electrostatic latent image retainer after transfer is slid, while the required voltage is applied. do.

By this voltage application, the remaining toner distribution after the transfer is disturbed and the toner distribution remaining after the transfer is uniform as a whole.

Therefore, the toner remaining after the transfer cannot cause ghost in the next image. In addition, since the charging of the latent electrostatic image retainer is not performed by so-called corona discharge, but is performed by a well-known mechanism of field emission or ion conduction, there is almost no discharge product and adversely affects the human body and the latent electrostatic image retainer. Can't give

Hereinafter, embodiments of the present invention will be described.

Example 1

3 is a cross-sectional view showing the main part of the recording apparatus according to the present invention. The developing apparatus 3 which develops the latent image of this electrostatic latent image retention body 1 with respect to the latent image retention body (photosensitive member) 1 is arrange | positioned.

The developing apparatus 3 incorporates a toner carrier 4, and the toner particles 2 charged by the toner carrier 4 in the same polarity as the electrostatic latent image retainer 1 are electrostatic latent image retainers ( It is supplied to the surface 1) and constitutes a structure in which the toner particles 2 are not adhered to a portion in which no charge exists on the surface of the electrostatic latent image retainer 1 (or a portion of a small amount of charge).

The selective attachment of the toner particles is performed by the charge portion potential Vo on the surface of the electrostatic latent image retainer 1 and the potential of the non-charged portion on the toner carrier 4 in the above-described developing apparatus (developing means) 3. Voltage between (Ve)

Vb (| Ve | 〈| Vb | 〈| Vo |)

The toner adhesion to the electrostatic latent image retainer 1 is suppressed by the electric field between the charged portion on the surface of the electrostatic latent image retainer 1 and the carrier 4, and the non-electrostatic charge on the surface of the latent electrostatic image retainer 1 is applied. The toner 2 is attached to the latent electrostatic image retainer 1 by the electric field between the portion and the carrier 4.

On the other hand, the transfer device 5 for transferring the toner particles 2 attached to the electrostatic latent image retainer 1 to the image support 6, the electric field removal lamp 8, The conductive brush roller 13 and the exposure means 10 are arrange | positioned.

In the transfer described above, not all of the toners are generally transferred, and the toner 2 'remaining after the transfer remains on the image on the surface of the electrostatic latent image retainer 1 after transfer.

After the transfer, the electric charge on the surface of the latent electrostatic image retainer 1 is removed by the electric field removal lamp 8, and the electrostatic latent image is formed by the uniform charge by the conductive brush roller 13 and the exposure by the exposure means 10 again. Has become a configuration.

In this cleaner-free recording apparatus, the remaining toner 2 'after the transfer is brought to the developing step, and at the same time as the developing of the latent charge, the above-mentioned remaining toner 2' is transferred to the developing apparatus 3.

Strictly speaking, the toner 2 'remaining after the transfer in the latent image charged portion (i.e., the unexposed portion or the non-image portion) formed by the exposure of the exposure means 10 has the same polarity as the latent image by the conductive brush roller 13. Is clearly charged.

For this reason, the toner carrier 4 is moved to the toner carrier 4 side by an electric field (that is, an electric field due to the potential difference between Vo and Vb) that suppresses the movement of the toner particles 2 from the toner carrier 4 to the electrostatic latent image bearing 1. Lose.

At the same time, the remaining toner 2 'remaining after the transfer in the non-charged portion (i.e., the exposed portion or the image portion) receives the force from the toner carrier 4 toward the electrostatic latent image retainer 1, and thus the electrostatic latent image retainer 1 Remaining on the surface.

In the non-charged portion where the remaining toner 2 'remains after transfer, new toner particles 2 are transferred from the toner carrier 4, and cleaning is performed simultaneously with development.

The recording apparatus according to the present invention is not provided with means 11 for equalizing the residual toner image, which is basically the same as that of the recording apparatus shown in FIG. 2, instead of the corona charger 9; It is characterized in that the chargeable brush roller 13 to which a voltage is applied is used.

The conductive brush roller 13 described above is formed by planting conductive fibers (brushes) 14 having a volume resistivity of 10 ² to 10 ¹⁰ Pa.cm, preferably 10 ³ to 10 ⁸ Pa.cm, on the outer circumference thereof. The roller substrate 15 on which the 14 is to be planted is made of a rigid conductor such as a metal or an elastic conductor such as a conductive rubber or a conductive foam.

The thickness of the fibers constituting the brush 14 is preferably in the range of 0.5 denier to 10 denier, and the simulation density to be planted is preferably in the range of 5000 / cm 2 to 100,000 / cm 2 and the length of the fiber is 0.5 mm. The range of from 5.0 mm is preferable.

These values are mainly based on the request from the charging function described later.

The conductive substrate (roller substrate) 15 of the conductive brush roller 13 described above is configured such that an alternating current or direct current voltage is applied to the conductive substrate (roller substrate) 15 by an alternating current power source or a direct current power source through the ammeter 16 or a power source 17 connected thereto. It is.

However, when the electrostatic latent image retainer 1 is uniformly negatively charged, a negative voltage or a negatively biased AC voltage is applied to the conductive brush roller 13.

In this case, the rotation direction of the conductive brush roller 13 may be either the same direction or the reverse direction as the rotation direction of the electrostatic latent image retainer 1, but the linear velocity of the periphery is different from the surface speed of the latent electrostatic image retainer 1. It is preferable.

That is, the linear velocity of the conductive brush roller 13 is preferably faster or slightly slower than the linear velocity of the electrostatic latent image retainer 1.

In particular, the speed of 1.2 to 5.0 times is preferable with respect to the latent electrostatic image retainer (1). Moreover, it is preferable that the contact width of the electroconductive brush roller 13 and the electrostatic latent image holding body 1 shall be 0.5 mm or more.

For example, the linear velocity of the latent electrostatic image retainer 1 is 40 mm / sec, the outer diameter of the conductive brush roller 13 is 25 mm, the resistance value of the fiber constituting the conductive brush 13 is 10 ⁵ Pa.cm, and the length of the fiber. The line speed of the conductive brush roller 13, which constituted a condition of 2.5 mm, a fiber thickness of 3 deniers and a planting density of 40,000 pieces / cm 2, was 60 cm / sec and a DC voltage of -500 V at an AC voltage of 800 V peak as an applied voltage. The result at the time of overlapping a voltage and setting the contact width of the electroconductive brush roller 13 and the electrostatic latent image retention body 1 to 3 mm is shown below.

First, under the above conditions, the surface of the holding photosensitive member (electrostatic latent image retainer) 1 is uniformly charged to -450V to -500V.

The toner image was transferred to the transfer paper 6 from the well-known transfer apparatus 5 after laser exposure was performed on this charged surface and developed by the two-component developing method or the one-component nonmagnetic developing method. After the transfer, on the organophotoreceptor (electrostatic latent image retainer) 1, toner 2 'remaining after the transfer on the image is generated.

The surface of the organic photoconductor 1 to which the residual toner 2 'is attached is charged by the field removal lamp 8 and then reaches the position of the conductive brush roller 13 again.

The toner 2 'remaining after the above-described transfer is uniformized by the sliding frictional force of the conductive brush roller 13 and at the same time, the sliding of the toner 2' is performed by an alternating electric field.

At the same time, a negative charge is applied to the aforementioned surface of the organic photoconductor 1 by the conductive fibers 14 of the conductive brush roller 13 in contact with the surface of the organic photoconductor 1 so that the organic photoconductor 1 is uniform. The game is played.

Here, even when only a DC voltage of about -500V to -800V is applied by the conductive brush roller 13, the uniformity and charging effect of the same aspect can be obtained, but the remarkable effect can be obtained by overlapping the alternating current.

It is preferable that the AC voltage has a peak value and the frequency of 300V to 2000V ranges from 200Hz to 5KHz. In addition, it is preferable that the absolute value of the superimposed DC voltage is a predetermined electrostatic latent image retainer 1 potential or a value larger than this (particularly about 200 to 500 V).

As the material of the fibers 14 for the conductive brush roller 13 described above, those obtained by conducting a conductive treatment of rayon polyamide, acrylic, tetrafluoropolyethylene, or the like can be used.

In this way, the conductive brush roller 13 can achieve the uniformity of the residual toner 2 'and the charging of the organophotoreceptor 1 at the same time.

Example 2

Instead of the conductive brush roller 13 in the case of Embodiment 1, you may use the fixed conductive brush 13a shown in FIG. In addition, the fixed conductive brush 13a has a structure in which the fixed gas piece 15a is formed by planting conductive fibers 14 in the concave surface.

Also in this case, the electrical properties and effects of the same aspect can be obtained by setting the conditions substantially the same as those in the first embodiment.

In this embodiment, the contact width between the conductive brush 13a, i.e., the means for indicating both functions such as the charging function and the uniformity of the remaining toner image, and the electrostatic latent image retainer 1 is preferably 3 mm or more.

Example 3

In the case of Example 1, instead of the conductive brush roller 13, you may use the conductive roller 13b comprised as shown in the cross section at the principal part in FIG.

In this embodiment, when the electrostatic latent image retainer 1 becomes a rigid body, it is preferable to make the conductive roller 13b an elastic body.

In FIG. 5, the conductive rubber layer 18 is provided in the outer periphery of the metal shaft 15, and the surface layer 18a which becomes a conductive resin or an elastomer on the surface was illustrated.

Of course, the single layer type without the surface layer 18a may be sufficient.

In the above-described configuration of the recording apparatus, experiments were conducted using the conductive rollers having a surface roughness of 0.3 µmRz, 1.2 µmRz, or 15 µmRz, respectively, in the conductive roller 13b. It became.

The conductive material of the conductive roller 13b described above is suitable for the conductive rubber layer 18 and the surface layer 18a, except for the conductive shaft 15, of 10 ³ to 10 ¹⁰ Pa · cm and electrical and mechanical conditions. It is better to make it almost the same as the case of Example 1.

Example 4

In place of the conductive brush roller 13 in the first embodiment, a magnetic brush 19 constituted as shown in cross section in Fig. 6 may be used.

The magnetic brush 19 has a fixed or rotating sleeve 21 made of a nonmagnetic material around a fixed or rotating magnetic roller 20, and a magnetic particle-containing layer 22 is attached to the periphery thereof. .

As magnetic particles, iron powder, ferrite, and the like are used for the volume resistivity of 10 ² -10 ¹⁰ Pa · cm and the average particle diameter of 10 µm to 200 µm.

In this case as well, the same effects as those of the first embodiment can be obtained by electrically setting the same conditions as in the first embodiment.

Other electrical conditions may be substantially the same as in the case of the first embodiment. As described above, according to the recording apparatus of the present invention, the charging means or the means for equalizing the remaining toner image constitutes a structure which simultaneously and reliably performs charging of the electrostatic latent image retainer and uniformity of the remaining toner after transfer.

In addition, a cleaner-less recording apparatus capable of miniaturizing and reducing the price of the apparatus and easily outputting a good image without contamination by discharge products and always without ghost can be obtained.

Claims (23)

An electrostatic latent image retainer, charging means for uniformly charging the surface of the electrostatic latent image retainer, means for forming an electrostatic latent image by attenuating a part of surface charge by exposing the surface side of the electrostatic latent image retainer charged by the charging means; And an inverse developing means for forming a toner image by attaching toner on the latent latent image, and an electronic means for transferring the formed toner image on the image support, wherein the current toner is introduced into the developing means by the inverse developing means. A recording apparatus for developing an electrostatic latent image at the same time as suction recovery, wherein the charging means comprises a conductive roller that uniformly charges the surface of the latent electrostatic image retainer and equalizes the distribution of the residual toner. The recording apparatus according to claim 1, wherein the voltage applied to the conductive roller is an alternating voltage or a voltage to which an alternating voltage is applied. The recording apparatus according to claim 1, wherein the cross-sectional width of the conductive roll in contact with the surface of the latent electrostatic image retainer is set to 0.5 mm or more with respect to the rotational direction of the latent electrostatic image retainer. 3. The recording apparatus according to claim 2, wherein the voltage applied to the conductive roller is a negative voltage or a voltage biased to negative. A recording apparatus according to claim 1, wherein the conductive roller is composed of at least a roller main body and a conductive elastic layer formed and formed on the circumferential surface of the roller main body. 6. A recording apparatus according to claim 5, wherein a surface protective layer is provided on the surface of the conductive elastomer layer. A means for forming an electrostatic latent image by attenuating a part of surface charge by exposing the electrostatic latent image retainer, the charging means for uniformly charging the surface of the electrostatic latent image retainer, and exposing the surface side of the electrostatic latent image retainer charged by the charging means; And an inverting shape means for forming a toner image by attaching the toner to the electrostatic latent image, and a transfer means for transferring the formed toner image onto the image support, wherein the remaining toner is introduced into the developing means by the inversion developing means. In the recording apparatus which sucks and simultaneously develops an electrostatic latent image, the charging means has a bias voltage obtained by superimposing an alternating current voltage on a direct current voltage having the same polarity as the counter electrode of the toner contributing to the development, thereby applying the surface of the electrostatic latent image retainer. And a conductive contact for simultaneously charging and uniformizing the charging and distribution of the toner. Value. 8. The recording apparatus according to claim 7, wherein the cross-sectional width of the conductive contact of the electrostatic latent image retainer surface is set to be 0.5 mm or more with respect to the rotational direction of the electrostatic latent image retainer. 8. The recording apparatus according to claim 7, wherein the voltage applied to the conductive contactor is a negative voltage or a voltage biased to negative (-). 8. A recording apparatus according to claim 7, wherein the conductive contact is a conductive brush roller. The recording apparatus according to claim 10, wherein the conductive brush roller is composed of a roller base body and a group of conductive fibers planted on the circumferential surface of the roller base body. The recording apparatus according to claim 11, wherein the roller base of the conductive brush roller is a rigid metal. The recording apparatus according to claim 11, wherein the roller base of the conductive brush roller is an elastic conductor. The recording apparatus according to claim 11, wherein the resistance value of the conductive fibers planted on the circumferential surface of the roller base member of the conductive brush roller is 10 ² to ^{10 10} Pa · cm. 12. The recording apparatus as claimed in claim 11, wherein the thickness of the conductive fibers planted on the circumferential surface of the roller base of the conductive brush roller is 0.5 to 10 denier. 16. The recording apparatus according to claim 15, wherein the density of the conductive fibers planted around the roller base of the conductive brush roller is 5000 to 100,000 pieces / cm < 2 >. The recording apparatus according to claim 10, wherein the conductive brush roller is set to rotate at a speed different from that of the electrostatic latent image retainer. 18. The recording apparatus according to claim 17, wherein the rotational speed of the conductive brush roller is set to 1.2 to 5 times the rotational speed of the electrostatic latent image retainer. 8. The recording apparatus according to claim 7, wherein the conductive contact is composed of at least a roller main body and a conductive elastic layer formed and formed on the circumferential surface of the roller main body. 20. The recording apparatus according to claim 19, wherein a surface protective layer is provided on the surface of the conductive elastic layer. 8. A recording apparatus according to claim 7, wherein the conductive contact is a magnetic brush. 8. A recording apparatus according to claim 7, wherein the conductive contact is a conductive fixed brush. The recording apparatus according to claim 22, wherein the conductive fixed brush is composed of a conductive base body having a concave surface and a group of conductive fibers planted in the concave surface of the conductive base body.

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